This invention relates generally to systems and methods for producing food products and, in particular, the present invention relates to a continuous system and method for producing frozen food products.
Frozen food products, such as frozen yogurts, ice cream, and so forth are popular snack foods. Non-dairy frozen products, such as soy and rice-containing products, sorbets, and so forth, are also well-known. A variety of devices are used to produce frozen food products either continuously or in batches. Many of these devices use ammonia as a refrigerant. The ammonia is typically applied in a jacket surrounding a mixer.
Some commercial devices use cryogenic refrigerants, such as liquid nitrogen. A cryogenic refrigerant is typically contacted directly with the food product in a chamber having mechanical mixing means. However, a cryogenic refrigerant can be difficult to use because it so readily freezes a food product xe2x80x9crockxe2x80x9d hard due to its extremely cold temperature, e.g., liquid nitrogen has a boiling point of about xe2x88x92196xc2x0 C. at atmospheric pressure. Such xe2x80x9cover-freezingxe2x80x9d can prevent the mechanical mixing means from properly functioning. Furthermore, mechanical mixing means are often complex in nature and subject to wear and/or breakage.
U.S. Pat. Nos. 5,126,156 and 5,664,422 to, Jones, describe a device that uses liquid nitrogen for preparing and storing a free-flowing frozen dairy product. In Jones, the product exiting the mixing chamber has been frozen into small beads. The beads must be kept sufficiently cold to retain their free-flowing character so they can be removed from the mixing chamber with an auger to another container. The beads must then be warmed before consumption. This process is complex in both design and operation, and further requires a separate step to warm the end product prior to consumption.
Thus, what is needed is a device and method for producing a tasteful frozen food product that is simple in design and operation, yet is capable of operating in a portable and continuous manner.
An apparatus for making a frozen food product comprising a mixer having no moving parts is disclosed. The apparatus further comprises heating means external to the mixer. The premix and refrigerant combine inside the mixer to produce a frozen food product. The heating of the mixer raises the temperature of the mixer sufficiently to prevent crystallization of the mixer contents at the mixer wall, thus preventing xe2x80x9cover-freezing.xe2x80x9d In this way, plugging of the mixer is minimized and the end product exits the mixer unassisted by mechanical means, yet is still in a frozen state. Thus, it is now possible to produce a quality frozen food product using cryogenic refrigerants, without causing the end product to be at cryogenic temperatures.
The present invention has the further advantage of allowing adjustable quantities of refrigerant and premix to be used. The invention is simple in operation and is preferably operated in a portable and/or continuous manner, although the invention is not so limited. The resulting products can be made as a soft or hard frozen food product by adjusting various parameters, including, but not limited to, flow rates, jacket, temperatures, tube length, and so forth.
These and other features, aspects, and advantages of the present invention will become better understood with regard to the following description, appended claims and accompanying drawings.